diff options
Diffstat (limited to 'vendor/k8s.io/apimachinery/pkg/watch/mux.go')
| -rw-r--r-- | vendor/k8s.io/apimachinery/pkg/watch/mux.go | 65 |
1 files changed, 38 insertions, 27 deletions
diff --git a/vendor/k8s.io/apimachinery/pkg/watch/mux.go b/vendor/k8s.io/apimachinery/pkg/watch/mux.go index 0ac8dc4ef..0aaf01adc 100644 --- a/vendor/k8s.io/apimachinery/pkg/watch/mux.go +++ b/vendor/k8s.io/apimachinery/pkg/watch/mux.go @@ -40,15 +40,12 @@ const incomingQueueLength = 25 // Broadcaster distributes event notifications among any number of watchers. Every event // is delivered to every watcher. type Broadcaster struct { - // TODO: see if this lock is needed now that new watchers go through - // the incoming channel. - lock sync.Mutex - watchers map[int64]*broadcasterWatcher nextWatcher int64 distributing sync.WaitGroup incoming chan Event + stopped chan struct{} // How large to make watcher's channel. watchQueueLength int @@ -68,6 +65,7 @@ func NewBroadcaster(queueLength int, fullChannelBehavior FullChannelBehavior) *B m := &Broadcaster{ watchers: map[int64]*broadcasterWatcher{}, incoming: make(chan Event, incomingQueueLength), + stopped: make(chan struct{}), watchQueueLength: queueLength, fullChannelBehavior: fullChannelBehavior, } @@ -96,10 +94,15 @@ func (obj functionFakeRuntimeObject) DeepCopyObject() runtime.Object { // The purpose of this terrible hack is so that watchers added after an event // won't ever see that event, and will always see any event after they are // added. -func (b *Broadcaster) blockQueue(f func()) { +func (m *Broadcaster) blockQueue(f func()) { + select { + case <-m.stopped: + return + default: + } var wg sync.WaitGroup wg.Add(1) - b.incoming <- Event{ + m.incoming <- Event{ Type: internalRunFunctionMarker, Object: functionFakeRuntimeObject(func() { defer wg.Done() @@ -111,12 +114,11 @@ func (b *Broadcaster) blockQueue(f func()) { // Watch adds a new watcher to the list and returns an Interface for it. // Note: new watchers will only receive new events. They won't get an entire history -// of previous events. +// of previous events. It will block until the watcher is actually added to the +// broadcaster. func (m *Broadcaster) Watch() Interface { var w *broadcasterWatcher m.blockQueue(func() { - m.lock.Lock() - defer m.lock.Unlock() id := m.nextWatcher m.nextWatcher++ w = &broadcasterWatcher{ @@ -127,18 +129,22 @@ func (m *Broadcaster) Watch() Interface { } m.watchers[id] = w }) + if w == nil { + // The panic here is to be consistent with the previous interface behavior + // we are willing to re-evaluate in the future. + panic("broadcaster already stopped") + } return w } // WatchWithPrefix adds a new watcher to the list and returns an Interface for it. It sends // queuedEvents down the new watch before beginning to send ordinary events from Broadcaster. // The returned watch will have a queue length that is at least large enough to accommodate -// all of the items in queuedEvents. +// all of the items in queuedEvents. It will block until the watcher is actually added to +// the broadcaster. func (m *Broadcaster) WatchWithPrefix(queuedEvents []Event) Interface { var w *broadcasterWatcher m.blockQueue(func() { - m.lock.Lock() - defer m.lock.Unlock() id := m.nextWatcher m.nextWatcher++ length := m.watchQueueLength @@ -156,26 +162,29 @@ func (m *Broadcaster) WatchWithPrefix(queuedEvents []Event) Interface { w.result <- e } }) + if w == nil { + // The panic here is to be consistent with the previous interface behavior + // we are willing to re-evaluate in the future. + panic("broadcaster already stopped") + } return w } // stopWatching stops the given watcher and removes it from the list. func (m *Broadcaster) stopWatching(id int64) { - m.lock.Lock() - defer m.lock.Unlock() - w, ok := m.watchers[id] - if !ok { - // No need to do anything, it's already been removed from the list. - return - } - delete(m.watchers, id) - close(w.result) + m.blockQueue(func() { + w, ok := m.watchers[id] + if !ok { + // No need to do anything, it's already been removed from the list. + return + } + delete(m.watchers, id) + close(w.result) + }) } // closeAll disconnects all watchers (presumably in response to a Shutdown call). func (m *Broadcaster) closeAll() { - m.lock.Lock() - defer m.lock.Unlock() for _, w := range m.watchers { close(w.result) } @@ -194,9 +203,12 @@ func (m *Broadcaster) Action(action EventType, obj runtime.Object) { // until all events have been distributed through the outbound channels. Note // that since they can be buffered, this means that the watchers might not // have received the data yet as it can remain sitting in the buffered -// channel. +// channel. It will block until the broadcaster stop request is actually executed func (m *Broadcaster) Shutdown() { - close(m.incoming) + m.blockQueue(func() { + close(m.stopped) + close(m.incoming) + }) m.distributing.Wait() } @@ -217,8 +229,6 @@ func (m *Broadcaster) loop() { // distribute sends event to all watchers. Blocking. func (m *Broadcaster) distribute(event Event) { - m.lock.Lock() - defer m.lock.Unlock() if m.fullChannelBehavior == DropIfChannelFull { for _, w := range m.watchers { select { @@ -252,6 +262,7 @@ func (mw *broadcasterWatcher) ResultChan() <-chan Event { } // Stop stops watching and removes mw from its list. +// It will block until the watcher stop request is actually executed func (mw *broadcasterWatcher) Stop() { mw.stop.Do(func() { close(mw.stopped) |